[vectorIntrinsics] RFR: 8264321: Create a separate library for x86 Intel SVML assembly intrinsics

[Sandhya Viswanathan]

Intel Short Vector Math Library (SVML) based intrinsics in native x86 assembly provide optimized implementation for Vector API transcendental and trigonometric methods.
These methods can be built into a separate library instead of being part of libjvm.so or jvm.dll.

The following changes are made:
   The source for these methods is placed in the jdk.incubator.vector module under src/jdk.incubator.vector/linux/native/libsvml and src/jdk.incubator.vector/windows/native/libsvml.
   The assembly source files are named as “*.S” and include files are named as “*.S.inc”.
   The corresponding build script is placed at make/modules/jdk.incubator.vector/Lib.gmk.
   Changes are made to build system to support dependency tracking for assembly files with includes.
   The built native libraries (libsvml.so/svml.dll) are placed in bin directory of JDK on Windows and lib directory of JDK on Linux.
   The C2 JIT uses the dll_load and dll_lookup to get the addresses of optimized methods from this library.

Build system changes and module library build scripts are contributed by Magnus Ihse Bursie (ihse at openjdk.org).

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Commit messages:
 - Cleanup stub generator
 - Rename  assembly header files to .S.inc
 - Fix so all assembly files are properly handled
 - Only build for x86_64
 - Remove the need for foo.c on linux.
 - Fix building on Windows without foo.c.
 - windows svml dll
 - hotspot changes for libsvml
 - Hacky workarounds to make library compile.
 - Add first sketch of makefile
 - ... and 1 more: https://git.openjdk.java.net/panama-vector/compare/51659814...29e33a9f

Changes: https://git.openjdk.java.net/panama-vector/pull/53/files
 Webrev: https://webrevs.openjdk.java.net/?repo=panama-vector&pr=53&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8264321
  Stats: 1045 lines in 79 files changed: 90 ins; 321 del; 634 mod
  Patch: https://git.openjdk.java.net/panama-vector/pull/53.diff
  Fetch: git fetch https://git.openjdk.java.net/panama-vector pull/53/head:pull/53

PR: https://git.openjdk.java.net/panama-vector/pull/53